Conventionally, as a photoelectric converter, as described in, for example, FIG. 9 of Patent Document 1, there is known a type including: a light emitting element which emits light by converting an electric signal into an optical signal; a substrate on which an IC circuit for transmitting an electric signal to the light emitting element is formed and the light emitting element is mounted on one surface from the side opposite to the light emitting side of the light emitting element: and a waveguide which is arranged to extend from the light emitting element in the direction perpendicular to the one surface of the substrate and transmits the light emitted by the light emitting element. Note that in place of the light emitting element, it is also possible to use a light receiving element which receives light and converts the received optical signal to an electric signal.
In the photoelectric converter described in FIG. 9 of Patent document 1, a male electric connector which is attachable and detachable to and from a female electric connector provided on a wiring substrate, is provided on the other surface of the substrate, and the substrate and the wiring substrate are electrically connected to each other by connecting these electric connectors.
In the above described constitution, however, a waveguide is provided so as to extend from the light emitting element in the direction perpendicular to the one surface of the substrate, which causes the height of the whole device to be significantly increased.
Here, as described in FIG. 3 of Patent Document 1, it is conceivable that the light emitting direction of the light emitting element is adapted to be arranged in parallel with the wiring substrate by providing the electric connector on the side surface of the substrate. However, even in this manner, the device height at least corresponding to the size of the light emitting element and a control IC element is necessary, and hence it is not possible to significantly suppress the device height.    Patent Document 1: Japanese Patent Laid-Open No. 2001-42170